神九的主要挑战是手动对接

Shenzhou-9 is set to have a "kiss" in space with Tiangong-1 in the first automatic docking Monday afternoon Beijing time.
 
The spacecraft has already undergone five orbital changes to prepare for the automatic docking.

The three astronauts will enter Tiangong-1 through the docking passage to live and work there for five or six days. Afterwards, they will conduct a manual docking.

Ma Yongping, Deputy Director of the Beijing Aerospace Control Center, says the manual docking, the highlight of this space mission, cannot simply be considered a combination of manned space flight and unmanned automatic docking.

"The requirements for a manual docking are much stricter than those for an automatic docking. Since the two vehicles will be moving very fast in orbit at a speed of 7.8 kilometers per second, the astronauts must be very careful to ensure the vehicles remain a certain distance apart and do not collide with each other during the docking process."

Space engineers describe the manual docking metaphorically as threading a needle between two objects flying at high speeds to describe how difficult the procedure is.

The three astronauts performed mission simulations on the ground more than 1,000 times before they lifted off into space.

Ma Yongping says the tough and complicated conditions in space will be the main obstacle for the manual docking mission.

"Although the astronauts performed many maneuvers on the earth, there are still many uncertainties in outer space. It requires our spacemen to maintain healthy physical conditions and keep their balance in a state of zero gravity for a long period of time, in an attempt to manually dock with the space lab module."

Tang Geshi, an engineer from the Beijing Aerospace Control Center, says the two dockings will be coordinated to ensure a safe mission.

"Both dockings are very crucial to the entire mission. Should any accident occur in the automatic docking, the astronauts can handle the emergencies manually. Likewise, if the spacemen detect any malfunctions in the manual docking, our control center will immediately initiate our emergency response system to solve the problem. So the safety of the mission will be largely enhanced."

Shenzhou-9 also sent into space China's first female astronaut, 34-year-old Liu Yang, who will mainly conduct medical experiments in the Tiangong 1 space lab module.

The astronauts will work and live in space for some 10 days and are scheduled to return to earth in late June.

For CRI, I am Wei Tong.